Built for reliable performance, affordable accuracy and CMMG's Mk4 S 5.56mm Upper Group accepts your sling mounts, bipods and many other KeyMod-compatible accessories. CMMG's RKM14 KeyMod free-float handguard protects your fingers from hot metal. The 18" medium-taper barrel is crafted of 416 stainless steel. Muzzle features a removable A2 compensator attached with 1/2-28" threading. Forged 7075-T6 aluminum M4-type upper receiver. Covered by CMMG's lifetime quality guarantee. Made in USA.